232 Transactions of the Canadian Institute. [Vol. VII. 



had disappeared the second sound of the heart could be heard on 

 auscultation for about half a minute and then it too disappeared and 

 the animal was dead. 



This slight rise after the respiration had stopped occurred in all the 

 dogs poisoned with chloroform following on atropine, and probably 

 points to a circulation made more vigorous by atropine. Dr. Reichert, 

 of Philadelphia, in a recent article,^ shows that after the respiration has 

 been paralyzed by atropine, if the breathing be maintained artificially, 

 then even as much as six times the lethal dose of the drug may be 

 administered and yet recovery may ensue. He shows, as is of course 

 well known, that atropine kills by paralysis of the respiratory centre ; 

 that next the vaso-motor centre is poisoned ; and last of all the heart. 

 These results if confirmed emphasize the importance of artificial 

 respiration being continued if necessary for hours in cases of atropine 

 poisoning in man. 



In several dogs in which the respiration had stopped as the result of 

 an overdose of chloroform, I found that atropine seemed to have a 

 powerful antidotal action, acting in this respect very much as 

 Hydrocyanic acid does. In a fox terrier dog which was being anaes- 

 thetized by chloroform the respiration, subsequent to some struggling, 

 rather suddenly ceased. The canula had not yet been introduced into 

 the carotid. Artificial respiration was used without success. The 

 tongue was forcibly dragged upon and was seen to be deeply cyanosed. 

 The heart could not be heard on auscultation. 1/50 of a grain of 

 atropine was injected under the skin over the precordia, and the 

 swelling thus produced was rubbed until it disappeared. About one 

 minute later the heart was felt to be beating rapidly, artificial respira- 

 tion was stopped, and in a kw minutes natural respiration commenced 

 in a shallow manner and the animal recovered. Exactly the same 

 sequence of events occurred in another dog. Unfortunately in neither 

 of these animals had the canula been adjusted in the carotid, and there- 

 fore we are unable to produce any tracings. The former dog had had 

 ^ grain of morphia hypodermically thirty minutes before the 

 emergency occurred ; the latter had not had any. 



I reproduce one tracing from a case in which recovery from chloro- 

 form poisoning seemed at least to be hastened by the use of atropine. 

 In Tracing 49 the animal was so deeply poisoned by chloroform that 

 the respiration had already stopped. -Atropine was injected at 13. 



I Philadelphia Medical Journal, Jan. 19th, 1901. 



